A light-emitting device (e.g., laser (e.g., semiconductor laser diode (LD)) and light-emitting diode (LED)), a light-receiving device, a hybrid optical device, an optical integrated circuit, and the like are known as an optical device. In recent years, an optical device that emits blue light or white light (i.e., an optical device having a shorter emission peak wavelength) has been developed, and widely used. There is a tendency that the brightness of a light-emitting device having a short emission peak wavelength is significantly increased, and the amount of heat generated by such an optical device further increases.
A curable composition (optical device-securing material composition) is used as an adhesive and a sealing material for such an optical device.
Along with a recent increase in brightness of an optical device, however, a cured product of the optical device-securing composition may deteriorate due to long-term exposure to high-energy light or high-temperature heat generated by the optical device, whereby delamination or cracks may occur, for example.
In order to solve this problem, Patent Literature 1 to 3 propose an optical device-securing material composition that includes a polysilsesquioxane compound as the main component.
A polysilsesquioxane compound is a compound represented by (R0SiO3/2)n(wherein R0 is a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, or the like), and has intermediate properties between inorganic silica (SiO2) and an organic silicone ((R02SiO)n).
However, the optical device-securing compositions disclosed in Patent Literature 1 to 3 that include a polysilsesquioxane compound as the main component may not produce a cured product that exhibits sufficient heat resistance and delamination resistance while maintaining sufficient adhesion.
Therefore, development of a curable composition that can produce a cured product that exhibits high adhesion, excellent heat resistance, and excellent delamination resistance, and rarely produces cracks has been desired.
Patent Literature 4 discloses a semiconductor light-emitting device member that has a solid Si-nuclear magnetic resonance spectrum that has at least one peak selected from the group consisting of a peak whose peak top position is within the chemical shift range of −40 ppm or more and 0 ppm or less, and whose full width at half maximum is within a specific range, and a peak whose peak top position is within the chemical shift range of −80 ppm or more and less than −40 ppm, and whose full width at half maximum is within a specific range, has a silicon content of 20 wt % or more, and has a silanol content of 0.1 to 10 wt %.